Power Spectral Analysis of the Envelope Pulse-Width Modulation (EPWM) Transmitter for High Efficiency Amplification of OFDM Signals

Umali, Edwin M.; Yoshikazu, Toyama; Yamao, Yasushi

doi:10.1109/vetecs.2008.266

Cited by 8 publications

(3 citation statements)

References 5 publications

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“…These technologies include three classical technologies: an outphasing amplifier [4] proposed by Henri Chireix in 1935, Doherty amplifier [5] proposed by William H. Doherty in 1936, and envelope elimination and restoration (EER) technology [6] proposed by Leonard R. Kahn in 1952; and each of these has been under research for improvement [7 -12]. In addition to the above three technologies, new high-efficiency technologies such as envelope tracking (ET) technology [13], envelope pulse width modulation (EPWM) technology using a deltasigma modulator [14], and load-modulated balanced amplifier (LMBA) [15] have been reported. As is well known, there is a trade-off between good linearity and high efficiency in power amplifiers.…”

Section: Introductionmentioning

confidence: 99%

How to Design an Outphasing Power Amplifier with Digital Predistortion

Kimura

Kawasaki

2021

IEICE Trans. Electron.

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How to design an outphasing power amplifier with digital predistortionShigekazu KIMURA †a) , member and Toshio KAWASAKI † , Non-member SUMMARY For improving the fifth-generation mobile communication system, a highly efficient power amplifier must be designed for the base station. An outphasing amplifier is expected to be a solution for achieving high efficiency. We designed a combiner, one of the key components of the outphasing amplifier, using a serial Chireix combiner and fabricated an amplifier with a GaN HEMT, achieving 70% or more high efficiency up to 9 dB back-off power in an 800 MHz band. We also fabricated a 2 GHz-band outphasing amplifier with the same design. We applied digital predistortion (DPD) to control the balance of amplifying units in this amplifier and achieved an average efficiency of 65% under a 20 MHz modulation bandwidth.

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Section: Introductionmentioning

confidence: 99%

How to Design an Outphasing Power Amplifier with Digital Predistortion

Kimura

Kawasaki

2021

IEICE Trans. Electron.

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“…To solve the PAPR problem of OFDM signal at present, the main methods have inhibition PAPR [1][2],PA linearization [3][4],and enhanced pulse-width-modulation(EPWM) [5][6] etc. [1] [2] introduce signal distortion to reduce PAPR, and [3][4] introduce redundant information to reduce probability of peak or reduce the peak of OFDM signal.…”

Section: Introductionmentioning

confidence: 99%

“…[1] [2] introduce signal distortion to reduce PAPR, and [3][4] introduce redundant information to reduce probability of peak or reduce the peak of OFDM signal. Pre-distortion is introduced to offset the nonlinear distortion of PA in [3][4].OFDM signal is decomposed into phase signal and amplitude signal in [5] [6].Among them, the phase signal is used to modulate phase, the amplitude signal is converted to a pulse width modulator(PWM) signal using Sigma-Delta modulation, and then is used to modulate amplitude of the carrier waveform, so as to form a RF signal with constant envelope. inhibition PAPR and PA linearization techniques to improve the efficiency of PA is very limited.…”

Section: Introductionmentioning

confidence: 99%

A Constant Envelope OFDM Signal Generation Algorithm Based on Frequency Domain Noise Shaping

Gu¹,

Chen²

2014

AMM

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Presents a OFDM signal generation method which transforms general OFDM signal to constant envelope signal. Through out-of-band of original OFDM signal insertion synthetic noise signal, the composite signal in time domain is constant envelope, and in in-band can achieve a high signal-to-noise ratio. Simulations show that the method can be used in OFDM system to improve the efficiency of power amplifier. Simulations show that the method does not need too high sampling rate, at the same time there is no stability problems, compared to the high efficiency power amplifier based on time-domain Sigma-Delta modulation technology.

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